This invention relates to a transportation system and, more particularly, to a guideway system for light rail transportation.
Rapid mass ground transportation systems offer many benefits over non-mass transportation means such as the use of automobiles, particularly in metropolitan areas experiencing severe traffic congestion and pollution problems. Mass ground transportation may also be a desirable alternative for short-range as well as long-range air travel. Although there has been a general recognition of the need for a reliable, safe rapid transportation system, utilization of rapid transit systems has been hindered by the high cost of construction and operation as well as technical difficulties in developing an efficient and versatile light rail system.
Conventional approaches have not produced a light rail transportation system that is sufficiently versatile, efficient, and cost-effective to be a feasible substitute for non-mass transportation and air travel alternatives. For instance, some so-called light rail systems have rather heavy transportation modules due to the use of heavy undercarriage or a heavy power system, high traction requirements, high onboard fuel requirements, or the like. Systems that rely on traction drives tend to have difficulty with steep grades. Moreover, external elements such as severe weather conditions and contaminations can pose substantial difficulty in the operation and maintenance of light rail systems. Additionally, traction drive mechanisms employing wheels tend to produce a lot of noise as well as wear.
The present invention overcomes the difficulties and disadvantages of the prior art by providing simple solutions to specific problems associated with developing an efficient and cost-effective light rail transportation system. The invention provides a guideway system that does not depend on traction for movement. In a specific embodiment, the pod assembly is placed inside a guide tube, the exterior of which preferably supports and guides the vehicle as it moves along the tube. Motion is generated by providing a pressure differential inside the tube between the upstream region and the downstream region of the pod assembly. The pressure differential is preferably generated by a stationary power system that produces a vacuum on the downstream region or pressurizes the upstream region or both. The speed of the pod assembly is controlled by modulating the amount of gas flow through the pod, that is, from the upstream side to the downstream side of the pod. The speed of the pod assembly is increased by reducing the amount of gas flow through the pod assembly to thereby increase the thrust on it, and is decreased by permitting a larger amount of gas to flow past the pod assembly to decrease the thrust.
Because the thrust required to move the pod assembly is generated by stationary power systems, the vehicle does not require heavy on-board engines or drive trains. The pod assembly and guide tube are relatively light in weight and are well-suited for use in a light rail system. The guide tube can be elevated because of the light overall weight of the system, reducing right-of-way costs. When elevated, grading costs and requirements are significantly reduced.
A magnetic coupling apparatus is used to couple the pod assembly inside the guide tube with the transportation module outside the guide tube. The use of a magnetic coupling apparatus eliminates the need to mechanically connect the pod assembly and the transportation module with a strut extending through a longitudinal opening in the wall of the guide tube. This allows the interior of the guide tube to be a closed system and avoids the need for a seal assembly for maintaining a desired pressure differential in the guide tube as the strut knives through the longitudinal opening of the guide tube, thereby improving mechanical integrity and pressure integrity of the system. Moreover, the use of the magnetic coupling apparatus instead of a mechanical coupling device makes it easier to clean the exterior of the guide tube and coupling apparatus or clear those areas of debris such as the removal of ice and snow. Magnetic coupling also allows disengagement of the pod assembly and transportation module without any mechanical linkage or disengagement. Because the transportation module is supported by he exterior surface of the guide tube, the weight of the transportation module is not carried by the pod assembly.
In accordance with an aspect of the present invention, a transportation system for moving a transportation module comprises a thrust tube and a pod assembly disposed inside the thrust tube to be thrusted along the thrust tube. An inner magnetic coupler is disposed inside the thrust tube and connected with the pod assembly to be moved by the pod assembly. An outer magnetic coupler is disposed outside the thrust tube and configured to connect with a transportation module. The outer magnetic coupler is spaced from the inner magnetic coupler by the thrust tube and is magnetically coupled with the inner magnetic coupler to be moved by the inner magnetic coupler.
In some embodiments, an inner linkage is connected between the inner magnetic coupler and the pod assembly to prevent magnetic loading on the pod assembly by the inner magnetic coupler. An outer linkage is connected between the outer magnetic coupler and the transportation module to prevent magnetic loading on the transportation module by the outer magnetic coupler. At least the portion of the thrust tube between the inner magnetic coupler and the outer magnetic coupler is made of a non-metallic material.
In accordance with another aspect of the invention, a transportation system for moving a transportation module comprises a thrust tube and an inner drive member disposed inside the thrust tube to be thrusted along the thrust tube. An inner magnetic coupler is disposed inside the thrust tube and connected with the inner drive member to be moved by the inner drive member. An inner spacing member is disposed inside the thrust tube and spaces the inner magnetic coupler from the inner surface of the thrust tube by a preset distance. An outer magnetic coupler is disposed outside the thrust tube and is configured to connect with a transportation module. The outer magnetic coupler is magnetically coupled with the inner magnetic coupler to be moved by the inner magnetic coupler.
In specific embodiments, the inner support member spaces the inner magnetic coupler from the inner surface of the thrust tube by about 0.03 to about 0.5 inch. The inner support member comprises a plurality of rollers coupled between the inner magnetic coupler and the inner surface of the thrust tube.
In accordance with another aspect of the invention, a transportation system for moving a transportation module comprises a thrust tube and an inner drive member disposed inside the thrust tube to be thrusted along the thrust tube. An inner magnetic coupler is disposed inside the thrust tube and connected with the inner drive member to be moved by the inner drive member. An outer magnetic coupler is disposed outside the thrust tube and is configured to connect with a transportation module. The outer magnetic coupler is magnetically coupled with the inner magnetic coupler to be moved by the inner magnetic coupler. An outer spacing member is disposed outside the thrust tube and spaces the outer magnetic coupler from the outer surface of the thrust tube by a preset distance.
In specific embodiments, the outer support member spaces the outer magnetic coupler from the outer surface of the thrust tube by about 0.03 to about 0.5 inch. The outer spacing member comprises a plurality of rollers coupled between the outer magnetic coupler and the outer surface of the thrust tube.